1,721,603 research outputs found
Colonel P. Villa in Ciudad Juares.
No full textPhotograph of Colonel P. Villa in Cuidad Juares, Chihuahua
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Inundated Area Delineation Using MODIS Data: Towards a Global Scale Geo-Database of Flood Events
Full text linkThe availability of global and accurate information is the primary factor affecting the possibility of planning and managing effective disaster response strategies, above all in less developed countries. The second determinant factor that avoids the full spreading of remote sensing technologies is cost-effectiveness and steadiness of results. This paper illustrates a straightforward method for rapid retrieval of inundation maps at regional and global scale by processing MODIS data with the Spectral-Temporal Principal Components Analysis and Digital Terrain Model filtering. Case studies are presented for three different vulnerable regions in developing countries struck by a severe river flood during the last year (2005, from spring to fall): India, Pakistan and Romania. For all the events studied it was obtained an overall accuracy greater than 95% and a kappa coefficient grater than 0.70, demonstrating this methodology is very accurate in mapping inundated areas. Moreover, the integration with vector data (such as roads, railways or urbanized areas) may be used to fast detect infrastructure damages at regional and global scale. This work is the first step to develop a global geo-database of flood-affected areas, a basic tool for helping public administrators in efficiently managing natural hazards. This is especially useful for less developed countries, which unfortunately suffer the heaviest damages because of the high density of population and the scarcity of prevention and rapid response strategies
Rapid Response Flood Assessment using Minimun Noise Fraction and Composed Spline Interpolation
No full textEvery year floods cause enormous damages and loss of human life all over the world. Regarding the European Union, extreme floods are the most common type of natural disasters (44% of the total in the last decade) and in the future the number of flash floods is expected to rise. Recent works of the authors have focused on the development of a straightforward and efficient processing algorithm for analyzing and mapping flood damages using optical remotely sensed satellite data and digital terrain models (DTMs). In this paper are presented some improvements of the processing technique, both regarding the flood mapping and the water depth estimation. With respect to the first issue a new data transformation is introduced, replacing the Spectral-Temporal Principal Component Analysis (STPCA) with the Spectral-Temporal Minimum Noise Fraction (STMNF) transformation, while the peak water depth is obtained through more sophisticated interpolation methods. The STMNF based technique was applied to the data collected for the worst flood of the 20th century that struck the Piemonte Region (Italy) in 1994. Regarding the flood mapping, the STMNF method allowed to establish an overall accuracy of 97.09% with a kappa coefficient of 0.889, obtaining a user accuracy of 85.76% and a producer accuracy of 95.96%, with a lower commission error if compared to the previous STPCA method. Regarding the water depth computation, the best results were obtained using the 2nd order composed splines interpolator, obtaining an overall agreement with ground reference data of about 83%
Competitivitè et flexibilitè su système de production des districts. Le cas du secteur italien de la chaussure
No full textn.d
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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